Possible Duplicate:
Attempt to access SQL Server with the user SA
I'm suffering an attempted invasion by brute force. A bot is trying to figure out the sa password. How do I restrict logins 3 attempts in SQL Server?
Moreover, I would like to block an IP, how can I do this?
You can use a login trigger to restrict access from given ip addresses. I will dig out the code for you.
Technet video on how to do it here: http://technet.microsoft.com/en-us/sqlserver/Video/dd898898